1. Plane-wave scattering

1.1 Assumptions

For convenience, we use the word light here in a broad sense, whatever the frequency of the radiation under consideration. Since a frequency spectrum can be described by a Fourier transform, we restrict ourselves to monochromatic radiation. Light is modeled as an electromagnetic wave, described by Maxwell's equations (so we won't talk about photons). Scattering is quasi-elastic, i.e. it produces no frequency changes other than those due to the Doppler effect, or those (singular) from a finite frequency to a zero frequency resulting from the eventual absorption of light by the particles. The medium surrounding the particles is assumed to be non-absorbing.

• A distinction must therefore be made between single and multiple...